Disclosure summary
The attack vector is a potential Denial of Service (DoS). The vulnerability is caused by an insufficient check on the length of a decompressed domain name within a DNS packet. An attacker can craft a malicious DNS packet containing a highly compressed domain name. When the resolv library parses such a packet, the name decompression process consumes a large amount of CPU resources, as the library does not limit the resulting length of the name. This resource consumption can cause the application thread to become unresponsive, resulting in a Denial of Service condition.
Source-reported weakness categories
CWE-400
Source-specific records & product guidance
Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.
Microsoft Security Updates (CVRF) · 2025-Jul
Open original source · Updated Feb 17, 2026
The attack vector is a potential Denial of Service (DoS). The vulnerability is caused by an insufficient check on the length of a decompressed domain name within a DNS packet. An attacker can craft a malicious DNS packet containing a highly compressed domain name. When the resolv library parses such a packet, the name decompression process consumes a large amount of CPU resources, as the library does not limit the resulting length of the name. This resource consumption can cause the application thread to become unresponsive, resulting in a Denial of Service condition.
Maximum of vendor-reported product scores; products and fixed builds are associations, not a universal affected-version statement.
Microsoft maximum product score: 7.5
| Vendor | Product / association | Version / bounds |
|---|---|---|
| Microsoft update guide | cbl2 ruby 3.1.7-2 on CBL Mariner 2.0 | (MSRC status code 3) |
| Microsoft update guide | cbl2 ruby 3.1.7-3 on CBL Mariner 2.0 | (MSRC status code 3) |
| Microsoft update guide | azl3 ruby 3.3.5-5 on Azure Linux 3.0 | (MSRC status code 3) |
Vendor remediation references
- CBL-Mariner Releases · build 3.1.7-3 · product IDs 20243-17086, 20392-17086
- Vendor guidance · product IDs 20243-17086, 20392-17086
- CBL-Mariner Releases · build 3.3.5-5 · product IDs 20244-17084
- Vendor guidance · product IDs 20244-17084
Original records & references
- NIST NVD record
- CVE Program record
- msrc.microsoft.com — Vendor advisory
PUBLISHED 2025-09-03T19:24:27-04:00
MODIFIED 2026-02-17T20:22:14-05:00
INGESTED 2026-10-08T12:45:45-04:00